1. Field of the Invention
This invention relates to a package or flatpack which provides high heat dissipation, in particular for microelectronics.
2. Description of the Prior Art
It is known that current advances in the fabrication of integrated circuits and hybrid circuits result in heat dissipations per unit area which exhibit a constantly rising trend.
Removal of the heat thus produced must be performed by means of the package on which the circuit or circuits are mounted.
Under these conditions, the package must essentially ensure optimum heat resistance in order to be capable of removing a large number of calories per unit area of substrate (by way of example, heat resistances as low as 1.degree. C./W are desirable).
A hermetically-sealed package of a currently available type is thus already known and constituted by a body or cup of Fe-Ni-Co alloy in which lead-in bushings, also formed of Fe-Ni-Co alloy, are sealed with a borosilicate glass. A substrate is bonded or brazed to the base of the package which is a poor heat dissipator by reason of the fact that it is formed of Fe-Ni-Co alloy.